Improvement in heating-stoves



PATENT QFFICE.-

ALONZO C. RAND, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN HEATING-STOVES.

Specication forming part of Letters Patent No. 119,718, dated October 10,1871.

To all whom it may concern:

Be it known that I, ALONZO G. RAND, of the city of Chicago, in the county of Cook and State of Illinois, have invented certain Improvements in Coal-Burners, of which the following is a speciication:

This invention relates to heating the air which supports the combustion of coal in a stove or furnace of any kind; and consists in conducting said air one or more times around the lire-pot and in distributing it evenly to the coal, in the manner hereinafter described.

In the drawing, Figure I is a vertical crosssection of a plain cylinder-stove with my device for heating the air applied thereto. Fig. II is a similar view of the outer casing, but showing the spiral passages and upper distributing-compartment in elevation, the plane of section being Opposite to Fig. I. Fig. III is a horizontal crosssection in plane of line x x, Fig. I; Fig. IV, a bottom view of the grate.

A is a plain cylinder-stove, provided with a cast-iron fire-pot, B, which has a plain interior surface, b, and flanges or shelves arranged in the form of a double spiral or screw. Around the fire-pot, and in close contact with the corrugations, is an outer cylinder or jacket, C. The spirals are so formed as to aord two separate `air-passages, b2 b3, between the ridges of the corrugations and the outer cylinder C. D is the grate, formed with a hollow axle, d, and hollow bars d1 d1, pierced through their under surface with small holes d?. Eis the damper, through which air is supplied to feed the coalin the grate D. F is the damper which admits air to the inclosed space G, and thence through the small holes g g to the portion of the lire-box immediately above the coal. H is the door through which coal is supplied to the stove. I is a closetting door, by which the ashes, Snc., are removed.

The operation of the invention is as follows: The dampers E and F are first closed, and the fire is then started in the usual way by placing kindlings and coal on the grate I) and gniting them through the door I. [After the coal is lighted the door I is closed tightly and the damper E opened wide. The requisite air for combustion will then be drawn in through the damper E and downward through the air-passage b3, circling around the lire-pot B, in conformity with the spiral, and at length entering in a highlyheated state the hollow axle d, whence it is distributed through the small holes cl2 in hollow bars d1 to the incandescent fuel. When the draught has become well established the lower damper F is opened and air allowed to pass up the spiral passage b2 to the distributing-compartment G, and so through the small holes g g into the body of the fire-box, to assist in the more complete combustion of the gases and vapors arising from the heated fuel beneath. When the combustion becomes too rapid, as it soon will by aid of the heated air, the upper damper E is entirely closed, thus excluding the further admission of air beneath the burning coal. The lower damper F remains open as before, to supply the necessary oxygen for the complete combustion of the gases arising from the fire beneath. When it is necessary again to urge the fire the upper damper is again opened and allowed to remain so until the fire burns as rapidly as is desired, when it is closed once more, as before.

The principal advantage secured by my invention is the very important one of a more complete combustion than is possible in stoves and furnaces as heretofore arranged. The air which is fed to the fuel coming in contact with the highly-heated surface ofthe re-boX and gratebars becomes greatly expanded and its capacity for a chemical union with the carbon of the coal largely increased. Theresult is rapid combustion, which also involves combustion at a high temperature, and, therefore, and in that degree, more perfect. As the gases arising from the burning fuel are fed with a fresh supply of heated oxygen, there is no opportunity for the said gases to cool and condense into the condition of smoke; but the combustion is continued and completed at a high temperature and no smoke is formed. The whole device is simple in construction and principle, and is adapted to almost every descriptionof stove or furnace, and especially to locomotive-engines.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The distributing-compartment Cr, in combination with one or more spiral flues for supplying air heated in the manner described to the gases arising from burning coal.

2. The hollow grate D, with its axial passage In witness whereof I have hereunto signed d, iu combination with the spirit] air-passage b3, my mune in the presence of two slibseribing wita-s specified and shown. messes.

3. The air-heating and distributing-device, as A. C. RAND. enwhole7 consisting of the spiral air-passages b2 b3, the dempers E F, the distributing-compartment Witnesses: G, the hollow grate D with its tubular axle d, GEO. W. MIATT, allarra'nged andoperatngsubstantiallyas shown J. U. GRMFENHAGEN. (154) and set forth. 

